Debt - Summary of the Components of Interest Expense Related to the Company's Borrowings (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Schedule Of Interest Expenses [Line Items]                      
Amortization of debt discount/(premium), net                 $ 13,560 $ 13,572 $ 6,217
Total interest expense $ 26,163 $ 24,784 $ 23,548 $ 23,053 $ 27,589 $ 29,948 $ 28,051 $ 27,806 97,548 113,394 118,690
Facility fees                 2,100 2,100 2,000
Continuing operations and discontinued operations                      
Schedule Of Interest Expenses [Line Items]                      
Amortization of deferred financing costs                 9,306 9,896 9,070
Amortization of net losses related to interest rate swaps                 0 0 93
Amortization of debt discount/(premium), net                 13,560 13,572 6,217
Total interest expense                 144,069 190,127 196,586
Continuing operations and discontinued operations | Revolving Credit Facilities                      
Schedule Of Interest Expenses [Line Items]                      
Interest expense                 8,220 7,957 3,314
Continuing operations and discontinued operations | Term Note Payable                      
Schedule Of Interest Expenses [Line Items]                      
Interest expense                 6,594 9,793 5,218
Continuing operations and discontinued operations | Mortgages and Notes Payable                      
Schedule Of Interest Expenses [Line Items]                      
Interest expense                 68,530 111,049 143,233
Continuing operations and discontinued operations | Convertible Notes                      
Schedule Of Interest Expenses [Line Items]                      
Interest expense                 24,509 24,509 24,509
Continuing operations and discontinued operations | Senior Unsecured Notes                      
Schedule Of Interest Expenses [Line Items]                      
Interest expense                 $ 13,350 $ 13,351 $ 4,932